Blaster anniversary recalls network worm heyday

It's six years since the infamous Blaster worm crippled Windows systems worldwide.

The most damaging variant of Blaster (AKA Lovesan) first started spreading on 11 August 2003, reaching its peak on 13 August.

Security researchers reckon the original malware was created by Chinese VXers after they reverse engineered a Microsoft patch for a DCOM Remote Procedure Call (RPC) flaw in Windows. The worm was capable of spreading without user interaction and used scanning routines to spread. The malware caused widespread network congestion and infected hundreds of thousands of computers, which were rendered unstable and prone to crashing as a result.

Organisations that reportedly suffered network slowdowns or worse because of the worm include German car manufacturer BMW and Swedish telco TeliaSonera.

Once established on infected systems Blaster was programmed to flood windowsupdate.com without spurious traffic on 15 August. In the event little damage was caused because Microsoft had time to respond.

Media attention about the worm spawned copycat virus authors, including Minnesota teenager Jeffrey Lee Parson. Parson (AKA t33kid), then 18, was arrested for creating a variant of the worm in late August 2003. He was eventually jailed for 18 months. Another Blaster copycat author Dan Dumitru Ciobanu, then 24, was arrested by Romanian police for creating a relatively tame variant of the malware.

The worm would never have taken hold if basic Windows firewall was enabled by default. This change only came with Windows XP Service Pack 2 in August 2004.

That change, and the realisation that patching Windows systems were just as important as using up to date anti-virus software, are arguable the long term legacies of the worm.

Blaster was the penultimate entry in a line of highly damaging Windows-specific worms - Code Red and Nimda in 2001 and Slammer in January 2003. Sasser, which followed in May 2004, brought the dynasty to a close.

Since then the malware landscape has changed, with botnet agents, scareware and targeted Trojan attacks becoming far more of a problem. Worms still crop up from time to time but the era of high-profile, noisy megaworms like Blaster belongs to days long gone. ®